Field
Implementations of the present disclosure generally relate to methods and materials utilized in the patterning and etching of substrates. More specifically, implementations described herein relate to a hybrid carbon hardmask.
Description of the Related Art
Integrated circuits have evolved into complex devices that can include millions of transistors, capacitors, and resistors on a single chip. The evolution of chip designs continually requires faster circuitry and greater circuit density. The demands for faster circuits with greater circuit densities impose corresponding demands on the materials used to fabricate such integrated circuits. In particular, as the dimensions of integrated circuit components are reduced to the sub-micron scale, it is often necessary to use low resistivity conductive materials as well as low dielectric constant insulating materials to obtain suitable electrical performance for such components.
As feature sizes of integrated device patterns decrease, the critical dimension (CD) requirement of features becomes an increasingly important criterion for stable and repeatable device performance. Allowable CD variation across a substrate has also scaled with the scaling of feature CD. With lateral dimensions scaling faster than vertical dimensions, because of issues with device capacitance, high aspect ratios (HAR) are now prevalent within the semiconductor industry.
When such demanding aspect ratios and CD control are compounded with requirements of high etch selectivity, sidewall smoothness, and high tool throughput, the process window for any hardware configuration can become very small. In many situations, a small process window occurs when a number of process gases are incorporated into a complex etchant gas mixture combined with extreme hardware settings, such as very high RF bias powers, to achieve a fragile balance between sidewall passivation, etch rate, and mask selectivity. However, such small process windows typically suffer from performance limitations which cannot be tuned out of the etch process with currently available processes and materials.
Accordingly, there is a need in the art for improved hardmask materials and methods.